Another bit of a stumper on Ello: How do you figure out who's writing good posts?
The lesson from Google+ is that "following" notifications are all but useless. Someone following you may have any or multiple motivations, from benevolent to spammy to harassing or worse.
Otherwise, typically you'll only observe others posting comments to people you're already following. My experience with G+ is that even on a largish network (estimates for "actives" on G+ range from ~30 million to 300 million, the higher value cited by Google insiders, the lower seems to be a more personally plausible size based on the level of interactions on the network).
One of the best ways of finding interesting people on G+ for me has been Search, and my own use of that network went through a sea change as 1) search became more useful and 2) a sufficient back-catalog of interesting posts had developed that I could actually turn up interesting material.
I still consistently find that topics of interest to me are very thinly discussed, even when I step outside any possible filter/block bubble via an anonymous session. See this search for economist Mark Blyth, where, at this writing, my own posts are still at the top of the results stack, most have no +1s, and only one breaks double-digits in +1 activity.
Which is among the reasons I really want to see search come to Ello.
Some sort of reddit-esque "front page" of quality content, perhaps broken down by category and not emulating Google+'s dispicable and utterly worthless "What Snot" (they seem to have mis-typed this as "What's Hot") could also be useful. And a draw for those not already on the service to see what they're missing. Compelling content rather than a nagging log-in page is a vastly more effective advertisement.
ping: @cacheflowe @budnitz